_Harporhynchus redivivus_, *371. _Hatteria_, 312. Hawk, marsh, 352. Helmet shells, 255. _Heloderma horridum_, *317. Hemiptera, 197. Hermit-crab, 154, *153. Herodiones, 347. Heron, great blue, 348; green, 347. Herring, 284. _Heteredon platirhinos_, 321. _Hippocampus hippocampus_, *285. Holothuroidea, 121, 124. _Homo sapiens_, 398. Honey-bee, *218; brood-cells of, *219; building comb, *221; comb of East Indian, *222; cross-section of body of pupa of, *191. Honey-bees, 212. Honey-dew, food of ants, 223. Hornets, 217. Horse-fly, cornea of eye of, *186. House-fly, 202. Humming-birds, 356. _Hydra_, *47; structure and life of, 46. Hydrozoa, 96, 97. Hydrophilidæ, 207. _Hydrophilus_ sp., external structure of, *164; internal structure of, *167. _Hygrotrechus_, 198, *199. _Hyla pickeringii_, 300. _Hyla versicolor_, 300. Hymenoptera, 212. _Hyptiotes_ sp., and web, *238. Iguana, 318. Imago, 190. Injecting-masses, 451. Insect, pinned, *465; twig, *427; wingless, *181. Insecta, 157. Insectivora, 391. Insects, classification of, 191; collecting, 463; communal, 215; development and life-history of, 188; form and structure of, 181; killing-bottle for, *463; social, 215. Invertebrate, defined, 30. Islands, coral, 104, 106. Isopod, *151. Isopoda, 150. Jack rabbit, 390. _Janus integer_, *215. Jellyfish, *101. Jellyfishes, 92; colonial, 97. Joint-snake, 318. _Julus_, *327. June-beetle, 212. June beetles, 206. _Kallima_, *429. Kangaroo, 389. Katydids, 192. Kelp-crab, *152. Kill-deer, 349. Killing-bottle for insects, *463. Kingfisher, belted, 354. Laboratory, equipment of, 450. _Lachnosterna_, 212. Lady-birds, 209. _Lagopus_, 350. Lake-lamprey, 279. _Lampetra wilderi_, 279. Lamprey, *278; brook, 279. _Lampropeltis boylii_, *321. _Lampropeltis getulus_, 320. Lancelet, 278. Larks, horned, *358. _Larus marinus_, 345. Larva, 189; of Monarch butterfly, anatomy of, 177; parasitized, *420. _Lasiurus borealis_, 392. _Lasiurus cinereus_, *392. _Lasius flavus_, 223. Leeches, 136. Lemurs, 401. _Leucania unipuncta_, *211. _Lepidocyrtus americanus_, *181. Lepidoptera, 205. Leptocardii, 277. _Leptoplana californica_, *138. _Lepus campestris_, 390. _Lepus nuttali_, 390. Life-history, defined, 62. Life-processes, essential, 15. Limicolæ, 349. Limpets, 255, *248. _Littorina scutulata_, *248. Live cages, 457. Liver of toad, structure of, 41. Lizard, *309. Lizards, 316. Lobster, 151, 152. Locust, differential, 156; ear of, *187; red-legged, 156, *157; Rocky Mt., 156; structure and life of, 156; two-striped, 156. Locusts, 192. _Loligo_, 257. Longipennes, 345. Loon, 343.